U.S. patent number 5,117,978 [Application Number 07/680,412] was granted by the patent office on 1992-06-02 for sheath for monopolar needle.
This patent grant is currently assigned to Medelec, Inc.. Invention is credited to Arthur Blumenfeld, Bert D. Heinzelman, Jeffrey Stein.
United States Patent |
5,117,978 |
Blumenfeld , et al. |
June 2, 1992 |
Sheath for monopolar needle
Abstract
A monopolar needle assembly comprises a disposable insulated
needle having an uninsulated tip projecting from a needle stem and
a sheath for covering the needle. The protective sheath is
preferably plastic and injection molded. The needle is disposed
within a protective sheath until the needle is inserted into the
patient, thereby preventing contamination of the needle. As
embodied herein, the exterior and interior surfaces of the
protective sheath are tapered to conform essentially to the
elongated configuration of the needle. The portion of the sheath
proximate the needle stem includes flanges projecting from the
exterior of the sheath to prevent the monopolar needle assembly of
the present invention from rolling if it is dropped.
Inventors: |
Blumenfeld; Arthur (Brewster,
NY), Heinzelman; Bert D. (North Bergen, NJ), Stein;
Jeffrey (Milford, CT) |
Assignee: |
Medelec, Inc. (Pleasantville,
NY)
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Family
ID: |
26977209 |
Appl.
No.: |
07/680,412 |
Filed: |
April 4, 1991 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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552838 |
Jul 16, 1990 |
5042482 |
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310098 |
Feb 14, 1989 |
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Current U.S.
Class: |
206/365; 604/263;
600/373; 206/364 |
Current CPC
Class: |
A61B
5/296 (20210101) |
Current International
Class: |
A61B
5/0492 (20060101); A61B 5/0488 (20060101); B65D
083/10 () |
Field of
Search: |
;206/210,306,364,365,366
;604/192,263 ;128/642 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Fidei; David T.
Attorney, Agent or Firm: Baxley; Charles E.
Parent Case Text
This is a divisional of application Ser. No. 552,838, filed Jul.
16, 1990, now U.S. Pat. No. 5,042,482, which is a continuation of
abandoned application Ser. No. 310,098 filed Feb. 14, 1989.
Claims
What is claimed is:
1. An integral, one-piece sheath for use with a disposable
monopolar needle,
the needle defining an axis as well as proximal and distal ends and
provided with a male connector at the proximal end which is axially
insertable into a female recess provided in a support handle,
the female recess defined by a hollow housing which tapers radially
inwardly in the distal direction into the supporting handle,
said sheath positionable to cover the needle and characterized
by:
a proximal connector end provided with a tapered lip extendable
axially in a distal direction and arranged to deform elastically
for interference-fitting removable engagement with the housing
about the male connector end of the needle for centering the needle
in the female recess,
a substantially cylindrical barrel extending distally beyond the
lip,
a scabbard extending distally beyond the barrel to a distal end and
adapted to enclose the needle therein,
the barrel having an outer diameter greater than that of the lip
and the scabbard,
at least one flange projecting radially outwardly from the barrel
to prevent rolling of the sheath when the sheath is dropped.
2. The sheath as set forth in claim 1 further characterized by a
pair of the flanges disposed 180 degrees about the barrel.
3. The sheath as set forth in claim 2 further characterized in that
the scabbard is tapered from the barrel toward the distal end.
4. The sheath as set forth in claim 3 further characterized in that
the scabbard is provided with a wall which tapers in thickness
being thicker at the barrel than at the distal end.
5. The sheath as set forth in claim 4 further characterized in that
the distal end is provided with an axial opening.
6. The sheath as set forth in claim 5 further characterized in that
the wall of the scabbard is provided with a quasirectangular
cross-sectional shape with two opposing essentially planar flat
surfaces.
Description
BACKGROUND OF THE INVENTION
The present invention relates to a disposable monopolar needle
assembly and, more particularly, to a disposable monopolar needle
assembly having a detachable cord.
Monopolar needles have been found to have important medical
applications. Indeed, monopolar needles enable detection of
electrical activity in muscle fiber. As a result, such needles have
been used in conjunction with neurophysiological recording systems
to record, and thereby, diagnose a wide range of muscular and
neurological disorders.
Certain conventional monopolar needles contain an insulated needle
with an uninsulated tip. The exposed tip affords a relatively small
surface area for detecting electrical activity when inserted within
a patient. Unfortunately, however, the insulating coating has a
tendency to wear away from the tip through continued use of the
needle. Variation in tip exposure from wear along the insulated
needle distorts the shape of the recorded waveforms. Moreover, such
needles present a risk of transmitting diseases from patient to
physician or others when the needle is prepared for
sterilization.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a
monopolar needle assembly which is disposable. This insures an
accurate waveform recording since the tip exposure of each new
needle is consistent. The disposability of the needle also
eliminates re-sterilization and re-use, thereby reducing the risk
of transmitting diseases from the patient to individuals handling
the needle, such as when the needle is prepared for
sterilization.
Another object of the present invention is to provide a radiation
resistant, monopolar needle assembly which is suitable for
sterilization by gamma radiation. The monopolar needle assembly of
the present invention has a two-piece construction, making it
unnecessary to throw out the entire needle assembly after use.
An additional object of the present invention is to provide a
monopolar needle assembly which has an insertion tip consistent in
size, thereby improving the diagnostic yield of the needle
assembly.
A still further object of the present invention is to provide a new
and improved monopolar needle assembly that is inexpensive, not
complicated, and easy to assemble.
It is a further object of this invention to provide a monopolar
needle assembly having a detachable cord, thereby enhancing the
overall utility and accessibility of the needle assembly.
Additional objects and advantages of the invention will appear in
the following description, and other objects and advantages will be
obvious from that description. The stated objects and advantages of
the invention may be realized by the apparatus and methods
particularly pointed out in the appended claims.
To achieve the foregoing objects, and in accordance with the
purposes of the invention as embodied and broadly described herein,
the monopolar needle assembly of this invention comprises a
disposable, electrically conductive needle having an insertion tip
projecting from a needle stem. A brass connector pin is secured to
the needle stem of the disposable needle. Handle means supports the
connector pin and holds the disposable needle for insertion into a
patient or the like. The handle means includes a hollow, elongated
housing having an interior surface. The housing engages the
connector pin along the interior surface for rigidly connecting the
disposable needle to the handle means. An elongated sheath covers
the needle and is releasably attached to the handle means. The
monopolar needle assembly further includes means for electrically
connecting the connector pin to a recording system.
The accompanying drawings, which are incorporated in and constitute
a part of the specification, illustrate one embodiment of the
invention and, together with the summary description given above
and the detailed description given below, serve to explain the
principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded view of the monopolar needle assembly of the
present invention;
FIG. 2 is a cross-sectional view of a sheath taken along line 2--2
of FIG. 1;
FIG. 3 is a bottom view of a flanged end of the sheath shown in
FIGS. 1 and 2 and taken across line 3--3 of FIG. 2;
FIG. 4 is a cross-sectional view of the sheath taken along line
4--4 of FIG. 2;
FIG. 5 is an end elevational view of a handle shown in FIG. 1;
FIG. 6 is an exploded view of the handle and a connector pin
normally disposed within the handle, the handle being viewed in
cross-section along line 6--6 of FIG. 5;
FIG. 7 is an expanded view of ribs disposed along a hollow portion
of the handle encircled in FIG. 6;
FIG. 8 is a cross-sectional view of the handle of FIG. 6, in which
the connector pin is depicted to be disposed within the housing;
and
FIG. 9 is a plastic pouch for retaining the monopolar needle
assembly of the present invention prior to use.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference will now be made in detail to a presently preferred
embodiment of the present invention, examples of which are
illustrated in the accompanying drawings.
A preferred embodiment of the monopolar needle assembly of the
present invention is shown in FIG. 1 and identified generally by
reference numeral 10. As embodied herein, the monopolar needle
assembly 10 comprises an electrically conductive needle 12 for
insertion into a patient. The needle 12 includes an insertion tip
14 projecting from a needle stem 16. Preferably, needle 12 is made
of an electrically conductive material such as stainless steel.
Needle stem 16 is insulated for its entire length.
In accordance with the present invention, the monopolar needle is
disposable, and is therefore designed for one time use to insure
the needle is always properly sterilized. Accordingly, the needle
12 is radiation resistant and is not capable of being autoclaved,
so that it cannot be re-sterilized and re-used. As a result, the
needle 12 may be discarded and replaced with another needle after
each use. Therefore, the needle 12 always affords consistent tip
exposure with each use.
As embodied herein and shown in FIGS. 1 and 2, the present
invention includes a protective sheath for covering the needle. The
protective sheath, which is identified generally by reference
numeral 18, is preferably plastic and injection molded. The needle
12 is disposed within a protective sheath 18 until the needle is
inserted into the patient, thereby preventing contamination of the
needle. Moreover, the needle 12 is not resheathable, thus
preventing re-use and further sterilization of the needle.
As embodied herein, the exterior and interior surface of the
protective sheath 18 are tapered to conform essentially to the
elongated configuration of the needle 12. As shown in FIGS. 3 and
4, an interior surface 20 of the sheath 18 is quasirectangular in
cross-section, with two of the sides being rounded. The exterior of
sheath 18 adjacent insertion tip 14 of needle 12 is formed with an
opening 22. The portion of the sheath proximate needle stem 16
includes flanges 24 projecting from the exterior of the sheath 18.
Flanges 24 prevent the monopolar needle assembly of the present
invention from rolling if it is dropped.
In accordance with the present invention, the sheath is housed in a
nonreusable package. As shown in FIG. 9, a package, shown generally
at 28, includes a clear plastic pouch 29 enabling the sheath 18 to
be viewed within package 28. The sheath 18 is also made of a
translucent plastic material so that the needle length can thus be
seen through the package before the package is opened. The package
28 and the sheath 18 minimize handling of monopolar needle assembly
10 before each use, thereby minimizing the risk of contamination of
the needle 12.
As embodied herein and shown principally in FIGS. 6 and 8, the
present invention includes a connector pin, which is identified
generally by reference numeral 30. The connector pin 30 is
connected to the needle stem 16 of the disposable needle 12.
Preferably, the connector pin 30 is a substantially cylindrical
electrode. According to the present invention, the needle 12 is
secured to the connector pin 30. For example, the needle 12 may be
crimped into the pin 30. Also, the stem 16 of the needle 12 may be
mounted within a knurled (not shown) aperture 32. Any other
conventional methods, such as soldering, also may be used to
securely mount the needle 12 on the connector pin 30.
As embodied herein, the connector pin 30 includes a connector body
shown generally at 35. The connector body 35 has a needle-receiving
end 33 and a conductor end 34. Needle-receiving end 33 receives
needle stem 16. Connector body 35 is recessed in the middle as
shown in 38, for reasons discussed hereinafter. Conductor end 34
includes a probe 40 extending away from the connector body 35. The
probe 40 connects the connector pin 30 ultimately to a recording
device 36. Typically, the probe 40 is 0.040 inches in diameter and
mates with a standard electronic 0.040 female connector in
recording device 36. The next smallest section, recessed section
38, is typically 0.065 inches in diameter.
As embodied and broadly described herein, the present invention
includes handle means for supporting the connector pin and for
holding the disposable needle when inserting the needle into a
patient or the like. The handle means includes a hollow housing
shown generally at 42 having an interior surface 43. The housing 42
is preferably formed of plastic and includes a distal needle
portion 44 for housing needle-receiving end 33 of connector body.
The housing 42 also includes a conductor portion 46 extending from
the needle portion 44. The conductor portion 46 houses a proximal
conductor end 34 of the connector body 35. Finally, the housing 42
includes a probe portion 47 for housing probe 40. The probe portion
47 serves as a centering device to facilitate lining up the female
connector on the recording device 36 with the conductor body 35
housed in conductor portion 46. In addition, the probe portion 47
is connected to a conductor portion 46 by shoulders 49. The
shoulders 49 form a stop so that when needle 12 is withdrawn from
the patient the change the physician will lose his grip on the
needle is considerably lessened.
The sheath 18 is releasably attached to the needle portion 44 of
the housing 42. Interior surface 43 of housing 42 is tapered in the
shape of a frustum so that it decreases in diameter as it extends
rearwardly, and the interior surface of sheath 18 is tapered in the
shape of a complementary frustum so that it decreases in diameter
as it extends rearwardly. This arrangement allows the sheath 18 and
the handle housing 42 to mate together with an interference fit. It
is this interference with the resultant distortion of the plastic
of sheath 18 that keeps the sheath and the handle means
together.
The needle portion of the housing also includes engagement means
for securely holding the connector pin within the housing, and for
rigidly connecting the disposable needle to the handle means. As
shown in FIGS. 6 and 7 in particular, the engagement means includes
a plurality of radially extending ribs 48. Ribs 48 engage recessed
section 38 of the connector body 35 to secure the connector pin 30
in handle housing 42. The proximal connector pin 30 is press-fit
onto the interior surface 43 of the handle housing 42 until the
ribs 48 mate with the recessed section 38.
In addition, the recessed section 38 provides further advantages
for the connector pin 30. For example, the recessed section 38
reduces the amount of material that has to be moved when the needle
12 is crimped into pin 30. Also, the recessed section 38 serves as
the female part or mortise into which the male part or tenon of
handle housing 42 locks. This prevents the needle assembly from
slipping back and forth in the plastic handle housing as the
physician moves the needle in and out of the patient. This feature
is important because the physician moves the needle in increments
as small as 0.001 inch. Consequently, there must not be any motion
of the needle relative to the handle as the physician moves the
needle.
In accordance with the present invention, there is also provided a
means for electrically connecting the connector pin to the
recording device. The means for electrically connecting the
connector pin to the recording device includes a flexible
electrical cord 50 as shown in FIG. 1. The cord 50 is detachably
connected to the probe 40 of the connector pin 30 at one end. The
other end of the cord 50 is connected to recording device.
In operation, a user, such as a physician, removes a sterile
package 28 from the needle assembly 10 and removes the needle
assembly from the package. The physician connects the flexible cord
50 to the recording device 36 and removes the sheath 18 from the
needle 12. The physician then inserts the distal insertion tip 14
of the needle 12 into the patient. After the physician is done
testing the patient he removes the needle from the patient. The
physician then places the entire needle assembly into a "V" shaped
hole in a disposed container, such as a Sharps container. By
pulling the flexible cord 50 needle 12 separates from connector pin
30. The needle drops into the container for easy disposable,
without the physician ever having to handle the needle. The
monopolar needle assembly of the present invention thereby reduces
the risk of transmitting diseases from the patient to the physician
via the needle.
Additional advantages and modifications will readily occur to those
skilled in the art. The invention in its broader aspects is,
therefore, not limited to the specific details, representative
apparatus, and illustrative examples shown and described.
Accordingly, departures may be made from such details without
departing from the spirit or scope of the general inventive concept
as defined by the appended claims and their equivalents.
* * * * *